In order to explore the flow regeneration noise of the dual-mode muffler, a test bench was built. The flow regeneration noise and tailpipe noise were measured with the valve closed and opened respectively at different inlet flow rates by the methods of dual-microphone transfer function and the muffler static transmission loss. The test results show that the flow regeneration noise and the tailpipe noise are both reduced when the valve is opened, and the incident sound power of the flow regeneration noise at the outlet drops down to 1.1 dB, and the tailpipe noise down to 2.3 dB, which directly proves that the dual-mode muffler can help reduce the flow regeneration noise. Based on the test, a three-dimensional model of the muffler was built, and the flow field simulation inside the muffler was performed by Fluent, obtaining the distribution characteristics of pressure, airflow velocity and turbulent kinetic energy. The simulation results indicate that pressure, airflow velocity and turbulent kinetic energy of the muffler are reduced when the valve is opened. The simulation and experimental results are basically in agreement.